scholarly journals Decay Analysis of 197Tl* Compound Nucleus Formed in 16O + 181Ta Reaction at above Barrier Energy Ec.m.~100 MeV

2021 ◽  
Vol 9 (1) ◽  
pp. 103-107
Author(s):  
Gayatri Sarkar ◽  
Moumita Maiti ◽  
Amandeep Kaur ◽  
Manoj K. Sharma
Keyword(s):  
Compound Nucleus ◽  
Cross Sections ◽  
Cluster Decay ◽  
Nuclear Radius ◽  
Interaction Radius ◽  
Mass Distributions ◽  
Barrier Energy ◽  
Shell Closures ◽  
Fragmentation Potential ◽  
Decay Path

The decay dynamics of 197Tl* compound nucleus has been studied within the framework of the dynamical cluster-decay model (DCM) at above barrier energy Ec.m. ≈ 100 MeV using quadrupole deformed configuration of decay fragments. The influence of various nuclear radius parameters on the decay path and mass distributions has been investigated by analysing the fragmentation potential and preformation probability. It is observed that 197Tl* nucleus exhibits the triple-humped mass distribution, independent of nuclear radius choice. The most preferred fission fragments of both fission modes (symmetric and asymmetric) are identified, which lie in the neighborhood of spherical and deformed magic shell closures. Moreover, the modification in the barrier characteristics, such as interaction barrier and interaction radius, is observed with the variation in the radius parameter of decaying fragments and influences the penetrability and fission cross-sections. Finally, the fission cross-sections are calculated for considered choices of nuclear radii, and the results are compared with the available experimental data.

Systematic decay analysis of 202Po∗ compound nucleus using Dynamical Cluster-decay Model

2019 ◽  
Vol 28 (12) ◽  
pp. 1950105 ◽  
Author(s):  
Pooja Kaushal ◽  
Manoj K. Sharma
Keyword(s):  
Cross Section ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Degrees Of Freedom ◽  
Cluster Decay ◽  
Channel Cross Section ◽  
Decay Model ◽  
Cross Section Formula ◽  
Collective Clusterization ◽  
Mechanical Fragmentation

The decay analysis of [Formula: see text]Po[Formula: see text] compound nucleus (CN), formed via [Formula: see text]Ca+[Formula: see text]Gd reaction, with inclusion of additional degrees-of-freedom, i.e., the higher multipole deformations, the octupole ([Formula: see text]) and hexadecupole ([Formula: see text]), the corresponding “compact” orientations ([Formula: see text]), and noncoplanarity degree-of-freedom ([Formula: see text]0), is investigated within the collective clusterization approach. The Quantum Mechanical Fragmentation Theory (QMFT)-based Dynamical Cluster-decay Model (DCM), wherein the point of penetration [Formula: see text], fixed via the in-built neck-length parameter [Formula: see text] in [Formula: see text] (equivalently, the “barrier lowering” [Formula: see text]), is used to best fit the channel cross-section ([Formula: see text]) and predict the quasi-fission (qf)-like nCN cross-section [Formula: see text], if any, and the fusion–fission ([Formula: see text]) cross-sections. We also look for other target-projectile (t-p) combinations for the synthesis of CN [Formula: see text]Po[Formula: see text].

scholarly journals Role of Polar vs Non-polar Configurations in the Decay of 268Sg* Compound Nucleus Within the Skyrme Energy Density Formalism

2021 ◽  
Vol 9 (1) ◽  
pp. 61-66
Author(s):  
Rajni Mittal ◽  
Kirandeep Sandhu ◽  
M. K. Sharma
Keyword(s):  
Experimental Data ◽  
Energy Density ◽  
Cross Section ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Fission Cross Section ◽  
Cluster Decay ◽  
The Impact ◽  
Adequate Agreement

The effect of polar and non-polar configurations is investigated in the decay of 268Sg* compound nucleus formed via spherical projectile (30Si) and prolate deformed target (238U) using the dynamical cluster decay model. The SSK and GSkI skyrme forces are used to investigate the impact of polar and nonpolar (equatorial) configurations on the preformation probability P0 and consequently on the fission cross-sections of 268Sg* nucleus. For non-polar configuration some secondary peaks corresponding to magic shells Z=28 and N=50 are observed, whose magnitude is significantly suppressed for the polar counterpart. The effect of polar and non-polar configurations is further analyzed in reference to barrier lowering parameter ΔVB. The calculated fission cross-section find adequate agreement with experimental data for chosen set of skyrme forces.

Fragment mass identification and related aspects in the decay of 40Ca* and 39K* nuclei

2014 ◽  
Vol 23 (10) ◽  
pp. 1450063 ◽  
Author(s):  
Gurvinder Kaur ◽  
Manoj K. Sharma
Keyword(s):  
Cross Sections ◽  
Entrance Channel ◽  
Cluster Decay ◽  
Channel Effects ◽  
Nice Agreement ◽  
The Cross ◽  
Fragmentation Potential ◽  
First Time ◽  
Mass Identification

The dynamics involved in the decay of light mass nuclei formed in asymmetric channels 12 C + 28 Si , 11 B + 28 Si and 12 C + 27 Al have been investigated using the dynamical cluster-decay model (DCM). In reference to the experimentally measured charge particle cross-sections, the fragment masses contributing towards the decay of 40 Ca * and 39 K * nuclei have been identified using spherical choice of fragmentation. Also, the role of entrance channel has been investigated by studying the decay of 39 K * nuclear system formed in two different reactions at same excitation energy. The behavior of fragmentation potential, preformation probability, penetrability and emission time, is analyzed to figure out the favorable mass fragments, their relative emergence and the entrance channel effects observed in the decay of light mass nuclei. In addition to this, the cross-sections for the light particles (LPs) and heavier charge fragments have been estimated for the compound nucleus (CN) decay. Besides this, one of the noncompound nucleus (nCN) process, deep inelastic collision (DIC) has been addressed in context of DCM approach for the first time. The cross-sections obtained in framework of DCM for both CN and nCN processes are found to have nice agreement with the available experimental data.

Quasifission mass distributions in the synthesis of 274Hs with 26Mg and 36S projectiles

2015 ◽  
Vol 30 (26) ◽  
pp. 1550129 ◽  
Author(s):  
R. Budaca ◽  
A. Sandulescu ◽  
M. Mirea
Keyword(s):  
Potential Energy ◽  
Configuration Space ◽  
Compound Nucleus ◽  
Degrees Of Freedom ◽  
Energy Landscape ◽  
Nuclear System ◽  
Mass Distributions ◽  
Mass Asymmetry ◽  
Potential Energy Landscape ◽  
Fragmentation Potential

The potential energy landscape for the [Formula: see text] synthesis is evaluated in the framework of the macroscopic–microscopic model. The fragmentation potential calculated in a configuration space characterized by five degrees of freedom associated to elongation, mass asymmetry, necking, and left/right deformations reveals the existence of several minima and some pronounced valleys. The valleys correspond mainly to the [Formula: see text] and [Formula: see text] quasifission channels, but also for some paths in the formation of the compound nuclear system. In this context, two different paths are obtained for the [Formula: see text] and [Formula: see text] entrance channels. The [Formula: see text] path leads to the formation of an isomeric minimum that decays by fission. The [Formula: see text] path evidences a larger probability for the formation of the compound nucleus. Therefore, the two distributions obtained for the associated quasifission processes are very different.

ROLE OF STATIC DEFORMATION AND COMPACT ORIENTATION OF TARGET NUCLEUS IN MEASURED FUSION, FUSION-FISSION AND CAPTURE CROSS-SECTIONS OF 244Pu+48Ca REACTION

2009 ◽  
Vol 18 (03) ◽  
pp. 601-619 ◽  
Author(s):  
RAJ K. GUPTA ◽  
NIYTI ◽  
MONIKA MANHAS ◽  
SIGURD HOFMANN ◽  
WALTER GREINER
Keyword(s):  
Angular Momentum ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Target Nucleus ◽  
Fusion Reaction ◽  
Orientation Angle ◽  
Moment Of Inertia ◽  
Static Deformation ◽  
Cluster Decay ◽  
Decay Channels

The dynamical cluster-decay model (DCM), with deformations and orientation degrees of freedom of the incoming nuclei and of outging fragments included, is used to study the excitation functions of the "equatorial" compact hot fusion reaction 244 Pu +48 Ca →292114* (compact orientation angle θc=90° for 244 Pu ). Considering the higher multipole deformations up to hexadecapole deformation β4 and configurations with "compact" orientation θc, the model is shown to give a good description of the measured individual light-particle decay channels σxn, here x=3, 4 and 5, and other decay channels, the fusion-fission σff and quasi-fission σqf (equivalently, capture σ cap ) with in one parameter fitting, the neck length ΔR. The quasi-fission is also considered as a cold process with an elongated "polar" configuration. The xn-channel cross-sections for collisions between nuclei with static deformations at their respective compact orientations are shown to be much more than for the case of the nuclei taken to be spherical, signifying the increase in fusion threshold for an intermediate hot fusion reaction to be associated with the static deformation of the target nucleus and its orientation at the point of collision in its path toward the (spherical) compound nucleus. The shell effects in both the potential and kinetic energy (the mass parameters) terms of the Hamiltonian are shown to be important. The free parameter ΔR of the model is shown to depend strongly on limiting angular momentum, which in turn depends on the use of sticking or non-sticking moment of inertia for angular momentum effects. For the sticking moment of inertia, the evaporation residue (neutron emission) is shown to occur almost promptly (largest ΔR), followed by the competing (hot/cold) quasi-fission and ending finally with fusion-fission of hot compound nucleus. Different ΔR's (equivalently, relative separations) for the three processes means to predict that the processes ER, ff and qf happen in different time-scales, in agreement with the indications of experiments.

ENTRANCE-CHANNEL EFFECTS IN THE DYNAMICAL CLUSTER-DECAY MODEL FOR THE DECAY OF HOT AND ROTATING COMPOUND NUCLEUS 48Cr AT ${\rm E}_{CN}^{*}\approx 60\, {\rm MeV}$

2006 ◽  
Vol 15 (03) ◽  
pp. 699-717 ◽  
Author(s):  
BIRBIKRAM SINGH ◽  
MANOJ K. SHARMA ◽  
RAJ K. GUPTA ◽  
WALTER GREINER
Keyword(s):  
Compound Nucleus ◽  
Cross Sections ◽  
Entrance Channel ◽  
Cluster Decay ◽  
Intermediate Mass ◽  
Excitation Energies ◽  
Decay Model ◽  
Independence Hypothesis ◽  
Channel Effects ◽  
Collective Clusterization

The entrance-channel effects in the decay of hot and rotating compound nucleus 48 Cr *, formed in symmetric 24 Mg +24 Mg and asymmetric 36 Ar +12 C reactions, are studied as collective clusterization process, for emissions of both the light particles (LPs) as well as the intermediate mass fragments (IMFs), with in the dynamical cluster-decay model (DCM). We find that the little differences observed in the decay of equilibrated compound nucleus 48 Cr *, formed in the two entrance channels with about the same excitation energy, are not in variance with the Bohr's independence hypothesis. In other words, the present study confirms the entrance-channel independence of the decay of compound nucleus 48 Cr * formed due to different target-projectile combinations with similar excitation energies. The collective clusterization process is shown to contain the complete structure of the measured fragment cross sections as well as average total kinetic energies.

A ALow-Energy Direct Channel Regge-pole Approach to α-C12Elastic Scattering .I

1981 ◽  
Vol 36 (5) ◽  
pp. 443-446 ◽  
Author(s):  
D. Majumdar ◽  
A. Roy Chowdhury ◽  
T. Roy
Keyword(s):  
Elastic Scattering ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Regge Pole ◽  
Direct Channel ◽  
Scattering Cross ◽  
Scattering Cross Sections ◽  
Background Effect

Abstract Differential scattering cross-sections for the elastic scattering of α by C12 at laboratory bombarding energies from 11.0 to 16.0 MeV have been evaluated in the direct channel Regge-pole formalism, taking into account the contributions from a few nearby dominant excited levels of the compound nucleus O16 and incorporating the background effect. The relevant pole-parameters have also been predicted.

scholarly journals Role of Different Model Ingredients in the Exotic Cluster-Decay of 56Ni*

2012 ◽  
Vol 57 (8) ◽  
pp. 796
Author(s):  
N.K. Dhiman
Keyword(s):  
Density Distribution ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Cluster Decay ◽  
Nuclear Radius ◽  
Technical Parameters ◽  
Ion Collisions

We consider the cluster decay of 56Ni* formed in heavy-ion collisions, by using different parameters proposed by different authors for the Fermi density distribution and the nuclear radius. Our study reveals that different technical parameters do not alter significantly the structure of fractional yields. The cluster decay half-lives of different clusters lie within ±10% for different Fermi density parameters and nuclear radii and, therefore, justify the current set of parameters used in the literature for the calculation of cluster decays.

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